Implantable active medical devices, such as cardiac rhythm management devices (pacemakers and defibrillators) and a variety of implantable muscle/nerve stimulators, for example, generally include a battery and battery-powered electronic pulse generator contained within a hermetically sealed housing or case within a lead connector housing or block attached to the exterior of the housing or case. The lead connector block (may also be known as connector header) is often affixed to the hermetically sealed housing with brackets, metal solder, laser or resistance welding, pins, screws, and/or a medical grade adhesive and other types of fasteners. The function of the lead connector block is to electrically and mechanically couple the electronic pulse generator with the therapy lead. The lead connector block is typically attached to the exterior of the hermetically sealed housing and is significant to defining the overall device shape and volume. Most often with each new device design, a new lead connector block must also be designed requiring substantial project resources and project schedule.
The electronics within the hermetically sealed housing are conductively coupled to the lead connector block via an electrical feedthrough assembly. Electrical feedthroughs serve the purpose of providing a hermetically sealed conductive path extending between the interior of a hermetically sealed container and a point outside the hermetically sealed housing that ultimately connects to the lead contacts within the connector header. The conductive path through the feedthrough usually includes a conductor pin or terminal that is electrically insulated from the hermetically sealed housing and hermetically bonded to a feedthrough housing or ferrule. The feedthrough housing is hermetically assembled to the device housing most often by laser welding. The feedthrough assembly can be one or more discrete feedthroughs, an array for feedthroughs as an assembly, or any other combination. While this arrangement has proven to be highly reliable, it involves a variety of expensive manufacturing processes and parts that necessarily increase the cost and overall volume of the resulting product. The connector housing assembly typically partially or substantially defines the overall shape of the device and requires extensive resources and development time and schedule with each new generation of devices. The method of attachment to the device exterior also requires significant development time and resources.
Ongoing efforts by the industry to reduce the size of the implantable device are desired. Early implantable pacemakers back in the 1960's were about the size of a hockey puck. With advances in microelectronics and integrated circuitry, significantly more features and capabilities have been embodied in implantable active medical devices that can be very small. Nonetheless, efforts to further reduce the size of implantable active medical devices continue in the industry.